Simple dice combat

Personally, I never understood why people use + modifiers.
Of course it is easy to simply add a number to the rolled dice. But it makes the game balance hard to get if you don't do your math.

I wonder if any one has ever thought of the impact that a modifier can have? To have a good view at this, I post here the several results of only D6.

Of course you could say that the number of wins increases slower and slower. But then I say that you need to look at the chance to loose as well. That one actually goes faster and faster. Once 0 loss is reached, the win chance is actually relatively "infinite".

I always divide the win chance with the loss chance. Because I think that that is the true strength of a die in battle.

When 1 versus 1 die is rolled and the winner is the die that has rolled the highest number (equal is a tie).
Then the results are:

D6 gives 36 possible results each roll:
+0 modifier: 15 win, 6 ties, 15 loss
+1 modifier: 21 win, 5 ties, 10 loss
+2 modifier: 26 win, 4 ties, 6 loss
+3 modifier: 30 win, 3 ties, 3 loss
+4 modifier: 33 win, 2 ties, 1 loss
+5 modifier: 35 win, 1 tie , 0 loss
+6 modifier: 36 win, 0 ties, 0 loss

When ties don't count as success or fail, the win factors are:
+0 modifier: 1
+1 modifier: 2.1
+2 modifier: 4.333
+3 modifier: 10
+4 modifier: 33
+5 modifier: infinite
+6 modifier: infinite

When ties do count as success, but not fail;
+0 modifier: 1.4
+1 modifier: 2.6
+2 modifier: 5
+3 modifier: 11
+4 modifier: 35
+5 modifier: infinite
+6 modifier: infinite

When ties don't count as success, but do as fail;
+0 modifier: 0.714
+1 modifier: 1.4
+2 modifier: 2.6
+3 modifier: 5
+4 modifier: 11
+5 modifier: 35
+6 modifier: infinite

I hope this gives a better understanding of the basics.
If you want, I could post for the other dice as well.